Problem: Cervical spine injuries (CSI) are serious, but rare events in children. In contrast, use of spinal precautions for trauma transport and radiographic evaluation for CSI in the emergency department (ED) are common and associated with adverse effects. As a result, millions of children who have no CSI are exposed to harm with no demonstrable benefit. The nation?s EMS systems need a Pediatric CSI Risk Assessment Tool that can be used to reduce the number of children who are transported in spinal precautions and irradiated unnecessarily. Leonard et al. and the Pediatric Emergency Care Applied Research Network (PECARN) retrospectively identified 8 risk factors that predict CSI in children. We also established the infrastructure to prospectively collect paired observations from EMS and ED providers and determined the test accuracies of the PECARN CSI risk factors. Goal: We propose to develop and test a Pediatric CSI Risk Assessment Tool that can be used by EMS and ED providers to determine which children warrant spinal precautions and cervical spine imaging after blunt trauma. Specific Aims: Using prospective observational data and information from a cognitive task analysis (ACTA) conducted with subject matter experts and relevant end- users, we will use a user-centered design approach to 1) Develop the Pediatric CSI Risk Assessment Tool in children with blunt trauma and 2) Validate the Pediatric CSI Risk Assessment Tool in a separate population of children with blunt trauma; and 3) Validate the Pediatric CSI Risk Assessment Tool with EMS observations from both the development and validation cohorts. Coordination: We will conduct this work at 15 PECARN trauma centers. Methodology: We will collect prospective observational data from EMS and ED providers regarding CSI risk factors for children who undergo emergency evaluation after blunt trauma and follow enrolled subjects for 28 days to determine CSI status. The study will occur in two phases: development (13,333 children; 240 children with CSI) and validation (8,889 children; 160 children with CSI). We will also capitalize on the research infrastructure to conduct an ACTA and tool prototype testing that will inform the iterative tool design to ensure that the tool is useable by EMS and ED providers. Evaluation: With data from the development cohort, a useable clinical decision support tool will be constructed that achieves >95% sensitivity, as well as adequate specificity (>40%) in the prediction of CSI. Subsequently, we will determine the performance characteristics of the tool in the independent validation cohort and in a cohort that has EMS provider observations. The ultimate output from this project will be a set of specifications for the Pediatric CSI Risk Assessment Tool that will include a validated clinical decision rule, validated tool designs and functions, and recommendations for implementation. Significance: An accurate, validated, and ultimately field-tested Pediatric CSI Risk Assessment Tool will safely limit unnecessary spinal precautions and radiographic testing for millions of children while helping identify those children who are truly at risk for CSI.